Cleanup fault tree analysis class.
Direct assignment of basic event container in probability analysis.
Introduce importance analysis: DIF, MIF, CIF, RRW, RAW.
Closes #75, closes #76, closes #77, closes #78, closes #79
Better formatting for output of importance calculations.
Documentation update about importance calculations.
Support for multiple input files with fault trees and model data.
Closes #83
Add high probability events in Chinese input file.
Report importance factors only for basic events in minimal cut sets.
Closes #82
Change probability calculation algorithm.

The equation is now expanded as in uncertainty analysis. This may lead
to merge of these two types of analysis.
Add mcs input for Chinese tree.
Remove coherency specific methods in probability calculations.
Simplify uncertainty analysis class.

Uncertainty analysis class privately inherits from probability analysis
class and uses functions and protected members for its own operations.
Fix the MCUB and rare event approximations for importance
calculations.
Fixes #84
Merge branch 'develop' into coverity-scan

Conflicts:
	.run_tests.sh
	doc/bugs.rst
	doc/probability_analysis.rst
	doc/speedlog.txt
	doc/todo.rst
	scripts/performance.sh
	tests/test_scram_call.py